mo&fran

44 minutes ago, Jimbo said:

Wow, now that looks like really good Food. Hope Royal is seeing what P&0 is putting out and Royal steps up their game!

Didn't Graham say they were eating in specialty restaurants.

Problem is that the Oasis class , in the US , has had new terminals built to accommodate the number of passengers these ships carry. To get by this in the Med, they load half in one port and the other half in the other port. 

55 minutes ago, Another_Critic said:

Which cruises out of Cape Liberty have gone to Aruba?

Explorer repo to PC to make room for Quantum.

3 minutes ago, blackjack24 said:

Wrong on Royals site and Skymiles cruises site. It isn't possible for there to be 8 different 7 night cruises in one month on the same ship. Do they have one of the ships wrong possibly. Looking to book asap but don't know what is wrong.

 

https://www.royalcaribbean.com/cruises?search=ship:OA|startDate:2024-07-01~2024-07-31

 

 

Every cruise takes some passengers from Barcelona and some from Civitavecchia on the same trip.

Only in Florida.  Weatherman says we have a cold front coming through overnight. Now we have a bone numbing 72 degrees.

My sailing coming up in October on Freedom have the earliest MTD at 7:15.

Rumors posted here talked about a third fixed time at 6:45.   

5 minutes ago, cruiselvr04 said:

This depends on where you are in the world. 

But it is in the US.

1 hour ago, chengkp75 said:

That is a two stroke, medium speed, trunk piston engine, like nearly every cruise ship has, and that Dali has for generators.  The main engine is a "slow speed" "crosshead" 2 stroke engine as per this:

 

Sorry, didn't watch the video all the way through to see it covers crosshead engines.  Also, all the "roots blower" (or engine driven blower) does not apply, as all are turbocharged.

Interesting.  Funny  that the  displacement comes from a narrow bore and long stroke.  I guess that reduces the weight of the piston itself and the rod over a wider bore and shorter stroke.

Thanks. 

I worked on gas turbines, no diesel engines. So I found this on youtube

Dali has a 2 stroke low speed 9 cylinder MAN diesel .

Looks like a second crane is on site.

The point is, they come in all sizes, from automobiles to ships.

The camera does pan back and forth. At the bottom of the screen is a red line. You put your curser at the end of the line, you can pull the end and reveal what was recorded earlier. there is a number displayed showing the time difference from live in H:M:s format. Also a small window pops up showing the picture at that point in time. If you press play it will pay from the point it time.

Baltimore port webcam is streaming live  on Youtube. I see 2 tugs with barges, one with a crane.

24 minutes ago, chengkp75 said:

When the propeller stops, the engine stops. When the propeller goes astern, the engine rotates in the other direction.  The engine is directly bolted to the propeller shaft.

 

Not sure what energy you are talking about.  Energy to drive the turbocharger comes from the main engine's exhaust gas spinning a turbine which is shafted to a compressor, which compresses the combustion air for the main engine.  So, when it starts, there is no energy from the exhaust (there isn't any exhaust), so the "auxiliary blowers" switch on and compress some air for the engine.  As the exhaust gas builds up in volume and temperature, the blowers switch off, and the turbo spins on its own, driven by the exhaust.

Oh, so it can rotate in either direction. Turbo chargers are not parasitic obviously , they get energy that would have been wasted, at by compressing inlet air improves power and efficiency (Cycle efficiency increases with higher pressure ).  With a turbocharger the powerplant becomes a combined cycle powerplant.

@chengkp75

Let me give you a little background about myself .  My degree is mechanical engineer.   I worked 42 years at Pratt & Whitney as a performance engineer designing engine cycles for supersonic applications, both commercial (NASA contract) and military.  I retire in 2008 at 65, but worked at outsourcing for another 6 years.  Even at 80 years old, I continue to be curious how things work.

7 minutes ago, chengkp75 said:

No.  Even at low speeds, where the turbocharger does not have enough energy to provide sufficient air to the engine, there are motor driven fans to provide that air.

Doesn't that energy come from the generator? does that mean if you want to stop, the engine turns off, or is there a clutch between the engine and propellor shaft.

29 minutes ago, chengkp75 said:

Didn't see your last question here.  Yes, the main engine relies on motor driven fuel pumps, oil pumps, water pumps, air compressors (both for starting and for control). The engine itself does nothing but drive the propeller.  But, generator engines are different, in that they basically have self-driven fuel, oil, water systems.  But, then there are further "layers" of systems that interact as well.  For example, the main engine has a "high temp" motor driven water pump and system that cools the engine directly (generator engine has engine driven high temp pump).  These "high temp" cooling systems are cooled in turn by a "low temp" cooling system with motor driven pumps (common to both main engine and generators).  The "low temp" cooling loop is then cooled by the "sea water" cooling system with further motor driven pumps.

So there are no parasitic losses on the drive engine at all.  

When I was in engineering school, there was a saying  "them that can, do, them that can't , teach" , do I sense a little of that here with our purported "experts".

15 minutes ago, chengkp75 said:

Hope this doesn't come across the wrong way, but let me ask you if you would pay for a bank of batteries and electric motors in your car, just in case the engine fails while you are on the highway?  For the most part, the ship has several layers of redundancy:  two generators on line while maneuvering (even though one could support the full load), another generator on standby to start immediately and come online in typically less than a minute, and finally an emergency generator that will start and come on line in less than 45 seconds.  But, again, even with steering, a ship without propulsion is just a brick with a rudder.  Think of steering your car using the back wheels, and how you would need to anticipate turning to keep the front end from clocking something.  And, even if you restore electrical power, the main engine will have shut down on various safety interlocks, and requires multiple auxiliary systems that will need to be restarted and the interlocks reset.  Unlike your car, the cooling water, lubricating oil, and fuel systems rely on external pumps driven by electric motors.

That is why I asked the question. Thank you.  Now I know something I didn't before. Once an engineer, always an engineer.  Am I correct that the generator powers the fuel pumps as well.

I wonder if they should have  a bank of batteries , so if the generator goes off line, they would provide power to keep the engine control and steering alive till the generator restarts?

Ship simulator recreates moments leading up to bridge crash in U.S. | Watch (msn.com)

15 minutes ago, not-enough-cruising said:

This guy's VLOG is losing credibility by the minute, some of the things he says just make ZERO sense and are in complete contradiction to what other (better known) outlets are reporting.

We are so lucky to have cheng here.

11 minutes ago, chengkp75 said:

Just remember that until the last few moments, the ship was in the shipping channel.  Also, like most cruisers, and one poster on this thread, I believe, perspective is deceiving, as it looks like the ships are almost touching the bridges as they go under, so how well a person could determine that a ship was too close to the bridge abutment is up in the air.

Is it possible there was a wind that could have pushed it out of the channel?

10 minutes ago, toad455 said:

Why weren't the construction workers told to get off the bridge? They were apparently on a break and the six that died were in their cars keeping warm.

 

On another note, Vision passengers are saying they'll dock in Bayonne. I'd assume their next two cruises prior to drydock will sail out of there, too.

Story I heard was the police were on the way to tell them but it was too late.

6 minutes ago, njkate said:

It’s not a requirement under the Key Bridge

Maybe they should have.